package com.lukk.util;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Random;

public class MD5Utils {
	// 全局数组
    private final static String[] strDigits = { "0", "1", "2", "3", "4", "5",
            "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };
    public MD5Utils() {
    }
    // 返回形式为数字跟字符串
    private static String byteToArrayString(byte bByte) {
        int iRet = bByte;
        // System.out.println("iRet="+iRet);
        if (iRet < 0) {
            iRet += 256;
        }
        int iD1 = iRet / 16;
        int iD2 = iRet % 16;
        return strDigits[iD1] + strDigits[iD2];
    }

    // 返回形式只为数字
    @SuppressWarnings("unused")
	private static String byteToNum(byte bByte) {
        int iRet = bByte;
        System.out.println("iRet1=" + iRet);
        if (iRet < 0) {
            iRet += 256;
        }
        return String.valueOf(iRet);
    }
    // 转换字节数组为16进制字串
    private static String byteToString(byte[] bByte) {
        StringBuffer sBuffer = new StringBuffer();
        for (int i = 0; i < bByte.length; i++) {
            sBuffer.append(byteToArrayString(bByte[i]));
        }
        return sBuffer.toString();
    }
    public static String GetMD5Code(String strObj) {
        String resultString = null;
        try {
            resultString = new String(strObj);
            MessageDigest md = MessageDigest.getInstance("MD5");
            // md.digest() 该函数返回值为存放哈希值结果的byte数组
            resultString = byteToString(md.digest(strObj.getBytes()));
        } catch (NoSuchAlgorithmException ex) {
            ex.printStackTrace();
        }
        return resultString;
    }
    public static String GetSaltCode(String strObj,String salt) {
        String resultString = null;
        try {
            resultString = new String(strObj);
            MessageDigest md = MessageDigest.getInstance("MD5");
            // md.digest() 该函数返回值为存放哈希值结果的byte数组
            resultString = byteToString(md.digest((strObj+salt).getBytes()));
        } catch (NoSuchAlgorithmException ex) {
            ex.printStackTrace();
        }
        return resultString;
    }
    public static String getRandomString(int length) { //length表示生成字符串的长度  
        String base = "abcdefghijklmnopqrstuvwxyz0123456789";     
        Random random = new Random();     
        StringBuffer sb = new StringBuffer();     
        for (int i = 0; i < length; i++) {     
            int number = random.nextInt(base.length());     
            sb.append(base.charAt(number));     
        }     
        return sb.toString();     
     }  
    public static void main(String[] args) {
    	String getSaltCode = MD5Utils.GetSaltCode(MD5Utils.GetMD5Code("delphis"), "delphis");
    	System.out.println(getSaltCode);
    	getSaltCode = MD5Utils.GetSaltCode(MD5Utils.GetMD5Code("zebra"), "zebra");
    	System.out.println(getSaltCode);
    	getSaltCode = MD5Utils.GetSaltCode(MD5Utils.GetMD5Code("tiger"), "tiger");
    	System.out.println(getSaltCode);
    	getSaltCode = MD5Utils.GetSaltCode(MD5Utils.GetMD5Code("squirrel"), "squirrel");
    	System.out.println(getSaltCode);
    	getSaltCode = MD5Utils.GetSaltCode(MD5Utils.GetMD5Code("mouse"), "mouse");
    	System.out.println(getSaltCode);
    	getSaltCode = MD5Utils.GetSaltCode(MD5Utils.GetMD5Code("hawk"), "hawk");
    	System.out.println(getSaltCode);
    	getSaltCode = MD5Utils.GetSaltCode(MD5Utils.GetMD5Code("elephant"), "elephant");
    	System.out.println(getSaltCode);
    }
}
